This proposal seeks funds to support a program of experimental research designed to provide basic information on peptide synthesis and conformation, ionic selectivity, kinetics of ion transport, lipid membranes and drug design. Porin, an outer membrane protein of E. coli will be reconstituted in artificial membranes. Chemical modification will be performed with the aim to produce pores that are highly anion or cation selective. Structural analogs of alamethicin will be synthesized; they are designed; (a) to solve the structure of this antibiotic and (b) to provide information on the molecular mechanism of the voltage-dependent conductances it produces in membranes. Kinetics of complexation will be measured with ion-binding cyclopeptides. New peptides designed (a) to have high dissociation rates and (b) to selectively bind biological molecules such as choline or amino acids will be synthesized. Methods will include solid-phase peptide synthesis, chromatography, two-phase extraction equilibria, Hummel-Dreyer chromatography, NMR-spectroscopy and electrical measurements in lipid bilayer membranes.